In the rest of this section, we will go into detail about Steps 1 to 3 mentioned above and show that the estimator \(\hat{\theta }_{N}^0\)  thus constructed satisfies (REF ); Step 4 is the standard method of moments [1]}.
For convenience, let us introduce some notation.
The multilinear-form notation
\(M[u] = \sum _{i_1,\dots ,i_k}M_{i_1,\dots ,i_k}u_{i_1}\dots u_{i_k} \in \mathbb {R}\nonumber \) 
